This work concerns the elucidation of the antigenic determinants recognized by cytolytic thymus-dependent lymphocytes (CTL). We have found that peptide fragments of both Sendai and influenza viral glycoproteins can stimulate these CTL in vitro from mouse spleen cells. One major goal is to isolate and characterize biochemically the structure of the stimulatory fragments. We will further test the physiological roles of these fragments in vivo with respect to induction of antibody and CTL formation. We will, in addition, be performing collaborative experiments together with Dr. Thomas Braciale in St. Louis to test the interactions of our fragments with cloned T cells in long term culture to understand the direct interaction of the fragments with individual T cells. We will also attempt to transfer the influenza glycoproteins from a liposome to a target cell for CTL using the Sendai HN and F proteins as carriers.